Recently I've been reading Marc J. Seifer's Wizard: The Life and Times of Nikola Tesla. Tesla, of course, has become a posthumous cult icon, and his appearances in various types of fiction... well, see for yourself. And i'm not immune. There's a fascinating story there.
Reading about him I see that he was indeed a brilliant man and inventor and a seemingly tireless worker. A mixture of unlikely odd jobs and skillful gambling - especially pool - paid his way through engineering school. From then on he had more ideas than really anyone knew what to do with.
He was also a great self-promoter who knew how to use the exoticism of his Serbian/Croatian background to his advantage. If television had become a mass medium during his lifetime he would have been on one talk show or another every day of the week.
Tesla is the perfect subject for romanticization through books and movies. Thomas Edison, though he suffered some reversals, is too much of an establishment figure. Someone like William E. Sawyer, a prolific inventor who died young well before the twentieth century started, is too obscure, his story too depressing. Nikola Tesla is Goldilocks' just right. Even those who root for the underdog, as a rule, don't choose the lowest ones.